#include <stdio.h>
long n,m,a[16][16];
     st[16],smax;

void back(int k)
{
int i,j,s,t;
if (k==m)
	{
	s = 0;
	for (i=0;i<=n;i++) {
		for (t=j=0;j<m;j++)
		if (st[j]) t+=-a[i][j];
		else t+=a[i][j];
		s+=t<-t ? -t : t;
		}
	if (smax<s) smax=s;
	return;
	}
st[k]=0; back(k+1);
st[k]=1; back(k+1);
}

int main()
{
long i,j;
freopen("flip.in","r",stdin);
scanf("%ld %ld", &n, &m);
for (i=0;i<n;i++)
for (j=0;j<m;j++)
	scanf("%ld", a[i][j]);
back(0);
freopen("flip.out", "w", stdout);
printf("%ld\n", smax);
return 0;
}